Exam 2 Flashcards
(62 cards)
A biochemical secreted by the egg jelly of sea urchin to attract sperms.
resact
Antennapedia is a Drosophila mutant resulting in an adult fly where the antenna is transformed into legs. This sort of mutant is known as a ________ mutant.
homeotic
Drosophila melanogaster is a good model organism to study early development.
False
Drosophila, like most insects, have embryos that undergo a type of cleavage in which there is a large central yolk mass surrounded by multinucleate cytoplasm that later undergoes cellularization. What is the term for this type of cleavage?
Superficial cleavage
During Drosophila development, there is a regulatory cascade of gene activation. The proper sequence for this cascade is _____.
bicoid, gap genes, pair-rule genes, segment polarity genes.
Epiboly
Infolding of a sheet (epithelium) of cells
For snail coiling, dextral (D) is dominant to sinistral (d). Coiling phenotypes are controlled by nuclear factors found in the oocyte cytoplasm. If a dextral (DD) female snail mates with a sinistral (dd) male then the F1 progeny will have ______________ coils.
dextral
For snail coiling, dextral (D) is dominant to sinistral (d). Coiling phenotypes are controlled by nuclear factors found in the oocyte cytoplasm. If a dextral (DD) male snail mates with sinistral (dd) female then the F1 progeny will have __________ coils.
sinistral
Genes involved in the sex determination in flies includes…
sex lethal and transformer genes
How does the formation of axes affect individual cell development in Drosophila embryos?
Chemical gradients run along these axes and influence cells.
In Drosophila, eggs are activated prior to fertilization.
True
In Drosophila, eggs are activated prior to fertilization.
True
In the absence of the bicoid protein, fly embryos will develop two heads.
False
In Trachemys turtles, what gene is expressed differentially by temperature in a way that makes it an important determinant of sex?
Dmrt1
In which species has external fertilization been most extensively studied, meaning that they are often used as a model?
Echinoderms such as sea urchins
In which taxonomic group or groups is sex determined primarily by the temperature at which the embryo develops during a specific time period?
Turtles and crocodilians
Ingression
Movement of epithelial sheets, spreading as a unit to enclose deeper layers of the embryo
Invagination
Inward movement of an expanding outer layer
Match the following type of cell movement in an embryo.
1. Infolding of a sheet (epithelium) of cells.
- Migration of individual cells from the surface into the embryo’s interior.
- Movement of epithelial sheets, spreading as a unit to enclose deeper layers of the embryo.
- Splitting of one cellular sheet into two more or less parallel sheets.
- Inward movement of an expanding outer layer.
__4__ Delamination
__1__ Invagination
__3__ Epiboly
__2__ Ingression
Match the following type of cleavage with the organism.
1. Discoidal cleavage
- Superficial cleavage
- Rotational cleavage
- Spiral cleavage
- Displaced radial cleavage
__3__ mammals
__1__ Birds
__5__ amphibians
__2__ Insects like drosophila.
__4__ snails
Order the events leading to the fertilization in sea urchin.
1.Chemotaxis to ensure species-specific attraction and activation
2.Contact with egg jelly triggering acrosome reaction
3.Release of proteolytic enzymes resulting in the digestion of jelly layer
4.Binding to the vitelline envelope
5.Fusion of sperm and egg cell membrane
Protostomes are animals that form the anus from the blastopore and the second opening becomes the mouth
False
Regardless of chromosomes present, what kind of gonad do mammals start out with?
A bipotential gonad
Secretion of anti-Müllerian hormone/factor (AMH or AMF) by Sertoli cells:
causes the Müllerian duct to regress by apoptosis in males
